1. Field of the Invention
The present invention relates generally to spectroscopy and, more specifically, to a method and apparatus for performing spectroscopic analysis of crystal or non-crystalline fibers.
2. Description of the Related Art
Presently, there is a need to develop new materials for solid state lasers. Research efforts are continuing to identify materials which extend the range of solid state laser wavelengths. It can be expected that many new materials with useful emission wavelengths remain yet to be discovered.
Optical spectroscopy plays an important role in the search for new solid state laser materials since spectroscopic analysis can be used both to characterize new laser materials and to improve their performance by optimizing crystal properties.
Growth of new laser materials in bulk, for example by the Czochralski, flame fusion, or heat exchange methods, is expensive and time consuming. An alternative, more practical method is to form single crystal fibers of the material to be studied. One method for forming crystal fibers is the laser heated pedestal method (LHPE) for the growth of single crystal fibers with diameters ranging from tens of micrometers to millimeters. Basically, the LHPE method results in rapid growth and reduced contamination and stress problems. A CO.sub.2 laser is split into two beams which are focused onto the end of a rod of the material to be grown into a fiber. When the fiber starts to grow, a source rod is fed into the laser beam to maintain a constant amount of volume. Typically, the diameter of the fiber is between one-half and one-quarter the diameter of the source rod.
The laser heated pedestal fiber growth process allows surveys for new laser materials as well as optimizing their lasing characteristics to be conducted more rapidly and less costly than conventional growth methods. However, their size and optical quality pose new problems of analysis thereof.